I take it that you wish to email a layout, not just the text of the form, right?
I much rather receive PDFs than html emails, so the following is definitely clouded by that preference.
1. You could print the layout as a PDF and attach it to your message. FileMaker 7 lets you specify the path to an attachment by calculation of by field value: big help. Both steps (the printing and the attaching) can be assisted by plugins. I'd search FileMaker's plugin directory...
http://www.filemaker.com/plugins/index.html
...for "PDF" for things to help on the printing side. On the attaching side, you don't really need anything special, as long as you know the name of the file you want to attach. If you need help naming and moving the file, you can look on FMI's site for "File Manipulation" plugins and use something like Troi file to rename and move the file.
2. You can use the iMailer plugin...
http://www.datadesigns.com/
...to send an image of the layout as a .pict (I believe).
3. Both of these approaches have their problems if you want to broadcast email to a ton of people. In that case you might be best making an html email and sending it through one of the email plugins like SMTPit.
Hope that provides a starting point.